Key for locks.



No. 838,910. PATENTED DEC. 18, 1906,

T. Wu SGHMBDER` KEY PoR LOCKS. f l' APPLICATION FILED 00T. 30, 1905 t 2 SHEETS-SHEET 1.

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PATENTED DEQ. 18, 1906.

P. W. SGHROEDER. KEY PoR LOCKS.

APPLICATION FILED OCT. 30, 1905 No. s38,91o.

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KEY FOF LOCKS.

Specification of Letters Patent.

Patented Dec. 1s, 1906.

Application led October 30, 1905. Serial No. 284.983.

To all wil/0722 it T11/(ty cm2/cern:

Be it known that I, FREDERICK VILLIAM SCHROEDER, a subject of the King of Great Britain, residing at 9 Arundel street, Strand, London, England, have invented certain new and useful Improvements in Keys for Locks, of which the following is a specification.

This invention relates to locks of the kind which are commonly known as Yale locks and to keys for operating the same.

According to the present invention the lever-teeth or serrated edge or edges of such keys are provided with a protective flap or iiaps, whereby the working parts are protected from attrition when not in use, and, further, it is rendered difficult to obtain an impression or model of the working parts of the key for purposes of fraud or otherwise.

The invention further involves a simplification of such locks by the reduction of the number of working parts thereof.

The improved lock or key is illustrated in the accompanying drawings, in which-M Figure l is a longitudinal section with lparts broken away, and Fig. 2 is a transverse section showing the key iitted in the lock and lock-pins withdrawn to enable the barrel to be rotated by the key. Fig. 3 is a side and end elevation of the key. Fig. 4 is a transverse section similar to Fig. 2, but showing the key depressing the lock-pins. Fig. 5 is a transverse section through the barrel between the lock-pins, showing the ward projecting into the key-slot. Fig. 6 is a side elevation in section of one of the locking-pins; and Figs. 7 and 8 are views similar to Figs. 2 and 3, showing a slightly-modified construction.

Mounted to slide transversely in the lock barrel or plug a, which is provided with a suitable longitudinal ward or wards m for the reception of the key t, by which it is rotated, are lockpins c, mounted in channels in said ward, which cooperate each with a corresponding lever or tooth t of the key. These lock-pins or pin-tumblers are urged in one direction by means of springs (l, which are compressed between the heads c of the lock-pins and collars or projections d in the interior of the lock-barrel to engage in a slot or in holes or recesses e/ in a i'ixed casing or sleeve e, surrounding the barrel, and are urged in the opposite direction by their hookshaped lower ends c2, encountering the teeth or levers b of the key as the latter is inserted into its wards in the keyway or path 7c.

The lock-pins or pin-tumblers are prefer-` ably bifurcated or U-shaped, one of the limbs of the fork-namely, the pin part c already described-being arran ed to slide in a transverse recess in the lockarrel a, while the other limb f of the fork slides in another transverse hole or slot or in a transverse slit g in the edge of the barrel. The tails f of the limbs cooperate with a slot or holes f2 in the fixed sleeve e, the arrangement being such that when the key of a given lock has been properly inserted therein the bifurcated lock-pins are retracted by their springs d, so as to hold the hooks .c2 in engagement with the corresponding rentrant serrations of the key b, the heads c, and the tails f of the bifurcated lock-pins being then flush with or at any rate not projecting beyond the surface of the barrel a, so that the latter may be turned by means of the 'key and the lockbolt thereby retracted. When any key differing materially from the proper key is inserted in the wards, then one or more of the heads or tails of the bifurcated lock-pins or the heads of some -pins and the tails of others will project into the slots or holes e f2 andv prevent the rotation of the barrel and the retraction of the lockebolt.

The projecting flap or hood b2 of the key may be formed in one piece with the key or may be separately formed and afterward attached to it, the edge of the iiap or hood being arranged to overlap the serrated edge of the key and form a shield or guard therefor, as shown in Fig. 2.

It may be convenient, inA order to increase the possible range of movement of the lockpins, to make a slot or groove or holes 7L in the protective hood b2, so as to allow the lower ends of the pins c to project into or through such grooves or holes as the key is pushed home into its position in the lock, such grooves, slots, or holes corresponding in position with the points of the teeth or of one or more of the teeth'of the key.

In` the modified construction shown in Figs. 7 and 8 the key h is formed substantially U-shaped in cross-section and a double set of serrations or levers b on internal shoulders on each limb of the U, as shown in Fig. 8. The serrations on each limb are thus protected by the hood or guard constituted by the other limb of the key. The serrations on IOO IIO

the two limbs may of course be varied in number, pitch, and depth in any desired manner. Cooperating With the double set of serrations b are two sets of spring-urged lockpins c/ which are substantially identical with those shown in Figs. 1, 2, and 4 and operate precisely in the manner already described.

y This application is a partial division of my prior application, Serial No. 255,401, iiled April 13, 1905.

Having described my invention., I claim- 1. A key having a projecting bit, and a hood normally overlapping the outer edge of the bit.

2. A key having a bit projecting at one side, and a hood carried by the opposite side of the key and normally overlapping the outer edge of the bit.

3. A key having one edge provided with a projecting bit, the opposite edge of the key being bent to form a hood embracing the outer edge of the bit.

4. A key having the parts adapted to engage the operative portion of the lock protected by means of an overlapping hood;

substantially as described.

5. A key having the parts adapted to engage the operative portion of the lock pro- 8. A key having one ledge of its shank provided with a series. of projecting bits, the other edge of the shank being bent to form a hood overlapping the outer edges of all of the bits.

9. A key having a projecting bit, and a hood rigidly carried by the key and overlapping the outer edge of the bit.

In testimonyL whereoil I affix my signature in presence of two witnesses.

FREDERICK W. SCI-IROEDER.

Witnesses:

EDWIN JOHN BENNETT, EUGENE C. BROWN. 

